One rainy night eight years ago, in Watertown, Massachusetts, a man was taking his dog for a walk. On the curb, in front of a neighbor's house, he spotted a pile of trash: old mattresses, cardboard boxes, a few broken lamps. Amidst the garbage he caught sight of a battered suitcase. He bent down, turned the case on its side and popped the clasps.

He was surprised to discover that the suitcase was full of black-and-white photographs. He was even more astonished by their subject matter: devastated buildings, twisted girders, broken bridges - snapshots from an annihilated city. He quickly closed the case and made his way back home.